Nakano T, Higashino K, Kikuchi N, Kishino J, Nomura K, Fujita H, Ohara O, Arita H
Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan.
J Biol Chem. 1995 Mar 17;270(11):5702-5. doi: 10.1074/jbc.270.11.5702.
Proliferation of vascular smooth muscle cells (VSMC) is triggered by two types of growth factors. One activates tyrosine kinase-type receptors and the other activates G-protein-coupled receptors. We found that a conditioned medium of rat VSMC contained a growth-potentiating activity for the latter type of growth factor, and we purified a 70-kDa growth-potentiating factor (GPF) from the conditioned medium. Analyses of GPF and its cDNA revealed GPF to be a gamma-carboxyglutamic acid-containing protein encoded by a growth arrest-specific gene, gas6, which related to protein S. GPF specifically potentiated cell proliferation mediated by Ca(2+)-mobilizing receptors. The presence of a specific binding site suggests that the effect of GPF is mediated by a receptor. Thus, GPF may be a new type of extracellular factor regulating VSMC proliferation.
